Tank plumbing question

[DaveS]

We are putting together a school tank and I wanted to get some input.  Tank has an overflow with 2 holes in it.  A 1" hole for drain and 3/4" for return.  This isn't exactly how I would have spec'ed a tank.  I like 3 drains for Bean Animal as it allows silence and redundancy. 

 

Does anyone here have a similar plumbing set up?  If so, are you concerned the single drain might clog and cause the tank to overflow?  Do you just use a Durso standpipe and have the pipe go below the waterline in the sump?

 

I'm tempted to use both holes for drain just so we have a backup and then have the returns come over the back.  But that kinda ruins the rimless tank look....

 

Comments and suggestions are welcome.  Thanks all.

[AlanM]

Possible to drill the back for the return and use the two holes for a Herbie?

[WheresTheReef]

My Deep Blue 90rr has the same 2 holes. Came with a 1.25" durso down to a 1" bulkhead. Return hole is 3/4". It was loud as I didn't want to put a valve on a single drain. I converted it to a Herbie and ran an external 3/4 over the outside. Couldn't drill since the glass is tempered. Runs nice and quiet this way. If you do this, make sure and cover the air hole on the durso pipe top since it allows air into the pipe.

Edited November 9, 2015 by WheresTheReef

[s2nhle]

small holes for drain and larger hole for emergency. alsoe  make a tall cap for the overflow so it will cover the return line.

[DaveS]

small holes for drain and larger hole for emergency. alsoe  make a tall cap for the overflow so it will cover the return line.

Not sure I understand what you are saying. Only have 2 holes so are you suggesting using both for drain? Tall cap?

[WilRams]

I am doing this soon myself. Planning to get a Deep Blue 60. I will use both holes in the overflow for a herbie. I will then drill the back glass for the return.

 

My other idea is to cap off both holes and cut out the overflow. Drill the back for an external overflow and return. 

[DaveS]

My other idea is to cap off both holes and cut out the overflow. Drill the back for an external overflow and return. 

 

I'm kinda digging that plan.  What if, instead of capping off the holes and cutting out the over flow, you drill two holes on the back of the tank within the space covered by the current overflow.  This way you basically have 4 holes in the overflow space instead of only 2.  You can use the existing overflow but use the 2 new holes for the drain plumbing and the 2 existing holes for return lines.  Hmmmm....

[s2nhle]

Not sure I understand what you are saying. Only have 2 holes so are you suggesting using both for drain? Tall cap?

Dyi overflow cap that is tall enough to hide the external hang over return line that comes over and out of your overflow box

[zygote2k]

FWIW, this is the theory that The Paranoid Reefers club purports- A single drain will clog and fail causing a flood.

In truth I have only ever seen this happen twice in 25 years of doing service. It's such a non-issue that the pure notion of it should be discarded.

The 1" drain will easily handle anything that that the 3/4" return can push through. It's not under pressure, so the extra diameter will easily drain whatever is in the overflow box.

A simple 1.5" durso standpipe with a 1" reducer at the bottom is the best answer here.

How the water enters the sump, now that's a different issue.....